class_docstr: Inverse Laplace transform methods are implemented using this
  class, in order to simplify the code and provide a common
  infrastructure.
  
  Implement a custom inverse Laplace transform algorithm by
  subclassing :class:`InverseLaplaceTransform` and implementing the
  appropriate methods. The subclass can then be used by
  :func:`~mpmath.invertlaplace` by passing it as the *method*
  argument.
code: def __init__(self, ctx):
      self.ctx = ctx
  
label_desc: Use image node_id 1 to create a new InverseLaplaceTransform object from inherited base classes: object with example: obj = InverseLaplaceTransform(ctx)